Electric cable



April l5, 1947. c, E. BENNETT ELECTRIC CABLE Filed sept. 2e, 1942 Patented Apr. 15, 1947 nach ELECTRIC CABLE Charles E. Bennett, Ridgewood, N. J., asslgnor to The Okonite-Callender Cable Company, Incorporated, Paterson, N. J., a corporation of New Jersey Application September 26, 1942, Serial No. 459,762

3 Claims. 1

This invention relates to an improvement in electric cables of the buoyant type. namely, cables which are adapted readily to iloat in sea water.

Among the objects of my invention is the provision ot a buoyant cable which is rugged in construction so as readily to withstand the rough usage to which such cables are subjected, sufciently flexible to permit the same to be handled and reeled without difllculty, and air cooled. By air cooling the cable I increase its currentcarrying capacity, thereby permitting a reduction in conductor size for a given duty as compared with prior buoyant cables.

In addition to air cooling the cable I provide for maintaining the air employed at a substantial pressure, say, 100 to 150 pounds per square inch, so that should the cable be punc tured below the water line, the water will be prevented from entering the cable, and the cable will remain afloat and usable until repairs can be effected.

More specifically my invention provides a construction wherein the cable is composed of a continuous hollow spiral core of metal, heavy cardboard, libre or other suitable material, about which the cable conductors are laid. Air is introduced into this hollow core from an air compressor which is mounted on a ship to which the cable is'attached when in use.

Still more specifically my improved cable comprises a hollow spiral core, such as above referred to, .and extending the length of the cable. Stranded immediately about this hollow spiral core is one of the cable conductors. About this conductor I apply an insulating layer of rubber, natural or synthetic, or rubber-like material. Over this insulating layer I strand a second conductor about which in turn I apply an insulating layer similar to the first one mentioned. In addi- `tion to the construction so far referred to, my cable comprises a series of floats of wood, for

instance, or other suitably buoyant material, these iioats not only providing additionalV buoyancy for the cable but also protecting the cable against mechanical indury.

In the accompanying drawing wherein I have illustrated one embodiment of my invention:

Fig. 1 is a digrammatic view showing my improved cable floating upon the water and attached to a ship; and

Fig. 2 is a sectional elevational view of ashort length or piece of the cable illustrated diagrammatically in Fig. l.'

Referring to the drawing in detail: My improved cable comprises a tubular core member 2 55 which has been illustrated as a hollow spiral.

This member may be composed of metal or treated paper or other suitable material and extends the length oi the cable.

Stranded immediately about this tubular core member is cable conductor 4. B designates an insulating layer over the conductor 4. This layer is of rubber. natural or synthetic, or other suitable exible rubber-like insulating material. 8 designates the second conductor oi the cable which is stranded about the insulating layer 8, and in turn is covered with a sheath i0 of rubw ber, natural or synthetic, or other suitable rubber-like material.

Threaded or strung upon the layer i0 are a plurality of floats i2 of highly buoyant material, such, for example, as wood or wood pulp treated to render the same highly water-resistant. In order that the flexibility of the cable will not be detrimentaily impaired the iloats i2 may be so shaped at their adjacent ends as in eect to provide a ilexible joint or they may be spaced sufficiently far apart on the cable so as not to interfere with flexing of the cable when the same is being handled or being reeled.

It will be understood of course that the weight to volume ratio oi my improved cable is such as to render the cable buoyant in Water.

When my improved cable is in operation, as above indicated,.1 propose to maintain the tubular core 2 under substantial internal air pressure, so that in practice the inner end of the cable is attached to an air compressor, which I have indi cated diagrammatically at il, mounted on the ship i6 to which the end of the cable is attached. This air compressor is capable c! maintaining an internal air pressure of say to 150 pounds to the square inch throughout the length of the cable. One of the functions of this air is to cool the cable conductors thereby increasing their our rent-carrying capacity for avgiven size conductor,

' or permitting ci reduction in the conductor size for a given duty.

In my copending application Serial No. 449,574, tiled July 3, 1942, I. have shown a cable of the buoyant type in which I employ water for the cooling medium. It will be appreciated that the present cable possesses certain advantages over my prior cable in that the pressure drop over a long length o! cable oi the type of the present application is negligible, while owing to the fact that airis so much lighter than water a buoyant cable can be produced the overall dimensions of which are much less than with the water cooled type.

A5 above mentioned, not only does the air function as a cooling medium but by maintaining the air at superatmospheric pressure, say 100 to 150 pounds per square inch, water is kept out of the cable, and should the cable be punctured, it will remain afloat and usable until repairs can be effected.

It is to be understood that changes may be made in the details oi! construction and arrangement of parts hereinabove described within the purview of my invention.

What I claim is:

l. A flexible electric cable comprising in combination a hollow core, a conductor stranded about said core, a flexible insulating layer of rubberlike material about said conductora seecond conductor stranded about said insulating layer, a flexible insulating layer of water impermeable rubber-like material over said second conductor, loats strung upon said last mentioned insulating layer, and an air compressor for suppb'ing air to the interior of said core in such Volume as to maintain the core under superatmospheric nternal pressure, the weight to volume ratio of the cable being such as to render the same buoyant in water.

2. A flexible electric cable comprising in combination a tubular hollow core of ilexible material wound in an open helix, a conductor stranded directly about said core, a flexible, electrically insulating, air and water impermeable sheath about said conductor, a second conductor stranded about said sheath, a flexible, electrically insulating, air and water impermeable sheath about said second conductory iloats strung upon the last mentioned sheath, the end of one float being convex and the adjacent end of the next float being concave to permit the iloats to telescope each other without impairing the flexibility of the cable, and means to supply compressed air to the said cable core at sufficient pressure to maintain the first mentioned sheath under sulcientiy high internal pressure as to prevent the entry o! water to the interior of the cable beneath the rst mentioned sheath in the event of puncture of said sheath; the weight to volume ratio of the cable being such as to enable the same to iloat in water.

3. A fiexible electric cable comprising in combination a tubular hollow core composed of paper tape wound in an open helix, a conductor strand ed directly about said core, a flexible sheath of air and water impermeable material immediately about said conductor, a second conductor stranded about said sheath, a flexible sheath of air `and water impermeable material immediately about said second conductor, wooden floats treated to increase their resistance to water strung upon said second sheath, the adjacent ends of adjacent floats being shaped to provide for tree flexing of the cable, and means for supplying air to the said core to maintain the first mentioned sheath under superatmospheric internal pressure to prevent the entry of water, in which the cable is Iloating, to the interior of the cable, beneath the rst mentioned sheath, the weight to volume ratio of the cable being such as to enable the same to float in water.

CHARLES E. BENNE'I'I.

REFERENCES CITED The following references are of record in the Ille of this patent:

UNITED STATES PATENTS Number Name i Date 2,193,977 Martin Mar. 19, 1940 1,524,124 Fisher Jan. 27, 1925 Re. 20,244 Peterson Jan. l2, 1937 2,050,991 Atkinson Aug. 11, 1936 1,866,611 A'el July l2, 1932 2,203,894 Cook June 11, 1940 2,268,223 Peterson Dec. 30, 1941 FOREIGN PATENTS Number Country Date 78,677 German Dec. 17, 1894 

